In the field of optical communication there is a strong demand for high transmission rate of information. The optical fibers used as the carrying medium are capable of transmitting the desired rates of information. However, the switching rate of the switches at the nodes and junctions of the communication networks are not fast enough to switch the desired information rates, carried by the optical fibers, resulting in bottlenecks produced by the switches. The switches used today in the optical communication networks are electronic switches that process the information electronically. The electronic switches require the use of Optical-Electrical-Optical (O-E-O) converters to convert the optical signals, received from the fibers, into electronic signals. The converted electronic signals are processed by the electronic switches for switching purposes. After the electronic switching the O-E-O converters convert the switched electronic signals, received from the electronic switches, back into their optical form to be sent into the optical fibers along the desired (switched) destination.
Unfortunately, the use of electronic switches in optical communication networks may have the following disadvantages:                1. Electronic switches require the use of O-E-O converters which are very expensive.        2. Prior to the switching action, the electronic switches store and buffer the information in a time consuming process.        3. Processing the information for the switching purpose is another time consuming action.        4. The switching process itself requires the activation of controllers, yet another time consuming process.        5. The electronic switches are generally large, power consuming, and difficult to maintain.        
Accordingly, there is a strong need for alternative switching technology that does not suffers from the above disadvantages. The use of all optical switches may save the need for O-E-O converters, however, the optical switches used today are even slower than the electronic switches and lack the intelligence needed for routing the information.
In addition, in the field of optical communication there is a strong demand for optical shaping, reshaping, and chopping of optical signals to perform transmission of optical information at a very high quality and very low Bit Error Rate (BER).
The implementation of ultra fast optical communication network faces, among other challenges, three obstacles. The first is the need to produce very fast modulators. The second is to maintain high quality optical signals along significant distances to keep very low BER. The third is to switch the information at a very high rate.
To overcome the first obstacle of producing the signals, at a very fast rate, there is a need for very fast modulators that are capable of producing very narrow optical pulses. Fast modulators are generally expensive and there are only a few types of modulators capable of producing narrow optical pulses suitable for use in extremely fast rate.
At a high transmission rate, the pulse quality of the optical pulses degrades very fast in a relatively short distance due to pulse broadening caused by chromatic and polarization-mode dispersions. Accordingly, to overcome the second obstacle of maintaining high quality optical signals along significant distances, many Optical-Electrical-Optical (O-E-O) regenerators may be distributed along the optical propagation path. O-E-O regenerators are very expensive and complex and thus dramatically increase the network cost in terms of infrastructure initial cost and maintenance cost. In addition, the O-E-O regenerators may reduce network reliability.
The third obstacle, of switching at a very high speed, remains unsolved due to the lack of an efficient, optical, switching alternative capable of replacing the electronic switches used for information routing.